(function () {
  const nav = document.querySelector('.xtx-elevator');
  const totop = document.querySelector('#backTop');
  window.addEventListener('scroll', function () {
    const n = document.documentElement.scrollTop;
    // if(n>=300){
    //   nav.style.opacity='1'
    // }else{
    //   nav.style.opacity='0'
    // }
    nav.style.opacity = n >= 300 ? '1' : '0';
  });
  totop.addEventListener('click', function () {
    window.scrollTo(0, 0);
  });
})();
(function () {
  const newGoods = document.querySelector('.xtx_goods_new');
  const popular = document.querySelector('.xtx_goods_popular');
  const brand = document.querySelector('.xtx_goods_brand');
  const topic = document.querySelector('.xtx_goods_topic');
  const elevator = document.querySelector('.xtx-elevator-list');
  elevator.addEventListener('click', function (e) {
    if (e.target.tagName === 'A'&& e.target.dataset.name) {
      const uname = e.target.dataset.name;
      switch (uname) {
        case 'newGoods':
          window.scrollTo(0, newGoods.offsetTop);
          break;
        case 'popular':
          window.scrollTo(0, popular.offsetTop);
          break;
        case 'brand':
          window.scrollTo(0, brand.offsetTop);
          break;
        case 'topic':
          window.scrollTo(0, topic.offsetTop);
          break;
        default:
          alert('cdhguvgvu');
      }
    }
  });
  window.addEventListener('scroll',function(){
    const n=document.documentElement.scrollTop
    elevator.querySelector('a.active') && elevator.querySelector('a.active').classList.remove('active')

    if(n>=newGoods.offsetTop&&n<popular.offsetTop){
        elevator.querySelector('a[data-name=newGoods]').classList.add('active')

    }else  if(n>=popular.offsetTop&&n<brand.offsetTop){
        elevator.querySelector('a[data-name=popular]').classList.add('active')

    }else  if(n>=brand.offsetTop&&n<topic.offsetTop){
        elevator.querySelector('a[data-name=brand]').classList.add('active')

    }else  if(n>=topic.offsetTop){
        elevator.querySelector('a[data-name=topic]').classList.add('active')
    }
  })
})();
